Publications by authors named "Lise Mathieu"

The pathophysiological mechanisms underlying Complex I (CI) deficiencies are understood only partially which severely limits the treatment of this common, devastating, mitochondrial disorder. Recently, we have shown that resveratrol (RSV), a natural polyphenol, has beneficial effects on CI deficiency of nuclear origin. Here, we demonstrate that RSV is able to correct the biochemical defect in oxygen consumption in five of thirteen CI-deficient patient cell lines.

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Mitochondrial respiratory chain (RC) disorders are the most prevalent inborn metabolic diseases and remain without effective treatment to date. Up-regulation of residual enzyme activity has been proposed as a possible therapeutic approach in this group of disorders. As resveratrol (RSV), a natural compound, was proposed to stimulate mitochondrial metabolism in rodents, we tested the effect of this compound on mitochondrial functions in control or in Complex I (CI)- or Complex IV (CIV)-deficient patients' fibroblasts.

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We and others previously reported that endogenous p53 can be located at mitochondria in the absence of stress, suggesting that p53 has a role in the normal physiology of this organelle. The aim of this study was to characterize in unstressed cells the intramitochondrial localization of p53 and identify new partners and functions of p53 in mitochondria. We find that the intramitochondrial pool of p53 is located in the intermembrane space and the matrix.

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In this study, we have compared several features of cell death triggered by classical inducers of apoptotic pathways (etoposide and tumour necrosis factor (TNF)-α) versus exogenous reactive oxygen species (ROS; hydrogen peroxide (H₂O₂), tert-butyl hydroperoxide (t-BHP)) or a ROS generator (paraquat). Our aim was to characterize relationships that exist between ROS, mitochondrial perturbations, Bcl-2 and caspases, depending on source and identity of ROS. First, we have found that these five inducers trigger oxidative stress, mitochondrial membrane permeabilization (MMP), cytochrome c (cyt c) release from mitochondria and cell death.

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Background: The mitochondrial inner membrane contains five large complexes that are essential for oxidative phosphorylation. Although the structure and the catalytic mechanisms of the respiratory complexes have been progressively established, their biogenesis is far from being fully understood. Very few complex III assembly factors have been identified so far.

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Starting from a transcriptome based study of the spatio-temporal expression of yeast genes encoding mitochondrial proteins of unknown function, we have identified the gene BCA1 (YLR077W). A FISH analysis showed that the BCA1 mRNA co-localized with the mitochondrial network. Cellular fractionation revealed that Bca1 is bound to the mitochondrial inner-membrane and protrudes into the inter-membrane space.

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Article Synopsis
  • The Oxa1/YidC/Alb3 family is crucial for forming respiratory and photosynthetic complexes in bacteria and organelles, specifically aiding in the assembly of mitochondrial proteins in yeast.
  • Researchers created random mutations in the Oxa1 protein to study how these changes affect the assembly of respiratory complexes, particularly noting the significant impact on complex V.
  • The study also uncovered important functional interactions between different transmembrane segments (TM2, TM4, TM5) and loops, indicating that TM4 and TM5 are essential for Oxa1's function.
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Article Synopsis
  • The Bcs1p protein, found in both yeast and humans, plays a crucial role in assembling mitochondrial respiratory complex III and has an important AAA domain.
  • The research involved creating various point mutants of yeast Bcs1p, primarily in its C-terminal region, and analyzing their impact on respiratory function and protein accumulation.
  • Key findings indicate that certain conserved amino acids are critical for the protein’s stability and its interactions with other proteins, highlighting the significance of specific regions in both yeast and human versions of Bcs1p.
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